HCH Spiral pipe Ovalizer.. Spiral pipe Ovalizer It is used for the ovalizer duct manufacturing.After spiral duct,the ovalizer duct machine expands it into standard size,with the character ... ,high efficiency,easy operation.It is indispensable for duct manufacturing. HCH Spiral pipe Ovalizer. Ovalizer duct processing range1,semicircular mould):Ø150,Ø200,Ø250,Ø300,Ø350 ...